AT3 Tactical ACE Pistol 3 MOA Red Dot Sight - 2 Dot Colors - MI MK2 Lower 1/3 Co-Witness QD Picatinny Mount Kit
or 4 interest-free payments of $82.49 with
6 Magazines Per Order: Due to extreme volume, we are limiting sales of magazines to 6 per customer order. This applies to individual and bundled magazines. AT3 reserves the right to cancel any order over the 6 magazine limit.
- Free standard shipping on orders $139+ details
- 90-day no-hassle returns policy
- Backed by the AT3 Lifetime Warranty! what it covers
Product description
AT3 ACE Red or Green Dot with Midwest Industries MK2 Lower 1/3 QD Mount
Features
- Available with a red or green 3 MOA dot
- Lower 1/3 co-witness height for use with standard-height AR iron sights
- RMR footprint provides direct compatibility between the ACE and MK2 mount
- Tool-free quick-detach lever allows fast optic removal
- Precision-machined mounting system supports reliable return to zero
- Multi-faceted adjustment nut accommodates variations in Picatinny rail tolerances
- Clamping system is designed to secure the mount without damaging the rail surface
- Shake Awake activation with a 5-minute auto-off
- Automatic brightness mode plus 12 manual brightness settings
- Up to 50,000 hours of battery life from one CR2032 battery
- 7075 aluminum optic housing with a hard coat anodized 6061 aluminum mount
This kit pairs the AT3 ACE with the Midwest Industries MK2 QD mount for a lower 1/3 co-witness setup on Picatinny-equipped rifles. The raised optic position keeps standard-height iron sights in the lower portion of the ACE window, while the adjustable QD lever allows the complete optic assembly to be removed without tools. Choose between a red or green 3 MOA reticle.
Note: Co-witness position may vary slightly depending on the firearm and iron sights used. Confirm that the selected mounting screws engage securely without bottoming out, and tighten the ACE mounting screws to 10-12 inch-pounds.
Specifications
- Optic Brand: AT3 Tactical
- Optic Model: ACE Pistol Red Dot Sight
- Mount Brand: Midwest Industries
- Mount Model: MK2 QD RMR Mount
- Mount MPN: MI-MK2-QDRMR1-3
- Optic Footprint: RMR
- Rail Compatibility: Picatinny
- Mount Height: Lower 1/3 Co-Witness
- Mounting System: Tool-Free Quick Detach
- QD Lever: Patented Elite Defense Design
- Return to Zero: Yes
- Reticle Options:
- Red 3 MOA Dot – ACE MPN: AT3-ACE-0
- Green 3 MOA Dot – ACE MPN: AT3-ACE-GRN-0
- Objective Lens: 22mm x 17mm
- Brightness Settings: 12 – 10 Daylight and 2 Night Vision
- Shake Awake: Yes, with 5-Minute Auto-Off
- Auto Brightness: Yes
- Night Vision Compatible: Yes
- Adjustment Range: 100 MOA
- Click Value: 1 MOA
- Eye Relief: Infinite
- Parallax: Fixed, Parallax-Free
- Battery: CR2032
- Battery Life: Up to 50,000 Hours
- Optic Material: 7075 Aluminum
- Mount Material: 6061 Aluminum
- Finish: Hard Coat Anodized Black
- Waterproof Rating: IPX7
- Shockproof Rating: 1,200 G for 5,000 Repetitions
- Optic Dimensions: 1.98″ Long x 1.17″ Wide x 1.08″ High
- Optic Weight: 1.35 oz with Battery and Cover
- Optic Mounting Screw Torque: 10-12 inch-pounds
What’s Included
- 1x AT3 Tactical ACE red dot sight in selected reticle color
- 1x Midwest Industries MK2 Lower 1/3 QD RMR mount
- 1x Midwest Industries optic mount tool
- 1x 1-degree shim plate
- 1x Windage, elevation, and battery cap tool
- 1x T10 Torx key
- 1x Lens wipe
- 5x Sets of ACE mounting screws
All 2 options on this page
- AT3 Tactical ACE Pistol 3 MOA Red Dot Sight - 2 Dot Colors - MI MK2 Lower 1/3 Co-Witness QD Picatinny Mount Kit - Reticle Color: Red | SKU: AT3-ACE-0-MI-MK2-QDRMR1-3
- AT3 Tactical ACE Pistol 3 MOA Red Dot Sight - 2 Dot Colors - MI MK2 Lower 1/3 Co-Witness QD Picatinny Mount Kit - Reticle Color: Green | SKU: AT3-ACE-GRN-0-MI-MK2-QDRMR1-3
Customer reviews
No reviews yet. Bought this one? Tell the next builder how it went.
Questions & Answers
No questions yet. Ask about fit, install or compatibility and our team answers within a business day.
Warranty & returns
Backed by the AT3 Lifetime Warranty!

All AT3 Tactical Brand Products carry a lifetime warranty against manufacturer’s defects.
This includes AT3 Red Dot Sights, Handguards, Iron Sights, and any other product that carries the “AT3 Tactical” or “AT3™” name. For other brands (ex. Magpul or Troy), please refer to the manufacturer’s warranty policy.
In the event that your AT3™ product becomes unusable, we will repair or replace the product at no charge to you.
If we cannot repair your product, we will replace it with a product in perfect working order of equal or better physical condition. The warranty is fully transferable, but we may require information about the original purchase to validate the authenticity of the product.
If your product is in need of warranty service, please contact AT3 Tactical to start the process
Our contact info is available here. To expedite processing, please provide your order information and description of the defect.
Please note: The AT3 Lifetime Warranty does not cover loss, theft, intentional damage or cosmetic damage that doesn’t affect the performance of the product.
90-day no-hassle returns
The AT3 Tactical store has a 90 day no-hassle return policy for products in good condition. You can view the full details of our return policy here.
If you encounter an issue or defect with a product after 90 days of your purchase, you can refer to the manufacturer for a warranty claim. Their policies are below.











